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Biomedical subjects

I Krüger

Publications and source records attributed to I Krüger.

At least 19 recordsLinked to original sources
PubMed2004

Hyaluronic acid and autologous synovial fluid induce chondrogenic differentiation of equine mesenchymal stem cells: a preliminary study.

Mesenchymal stem cells (MSC) have the potential to differentiate into distinct mesenchymal tissues including cartilage, which suggest these cells as an attractive cell source for cartilage tissue engineering approaches. Our objective was to study the effects of TGF-beta1, hyaluronic acid and synovial fluid on chondrogenic differentiation of equine MSC. For that, bone marrow was aspirated from the tibia of one 18-month-old horse (Haflinger) and MSC were isolated using percoll-density centrifugation. To promote chondrogenesis, MSC were centrifuged to form a micromass and were cultured in a medium containing 10 ng/ml TGF-beta1 or 0.1mg/ml hyaluronic acid (Hylartil, Ostenil) or either 5%, 10% or 50% autologous synovial fluid as the chondrogenesis inducing factor. Differentiation along the chondrogenic lineage was documented by type II collagen and proteoglycan expression. MSC induced by TGF-beta1 alone showed the highest proteoglycan expression. Combining TGF-beta1 with hyaluronic acid could not increase the proteoglycan expression. Cultures stimulated by autologous synovial fluid (independent of concentration) and hyaluronic acid demonstrated a pronounced, but lower proteoglycan expression than cultures stimulated by TGF-beta1. The expression of cartilage-specific type II collagen was high and about the same in all stimulated cultures. In summary, hyaluronic acid and autologous synovial fluid induces chondrogenesis of equine mesenchymal stem cells, which encourage tissue engineering applications of MSC in chondral defects, as the natural environment in the joint is favorable for chondrogenic differentiation.

Animals↗
PubMed2002

[Localization of primary small cell carcinoma with liver metastasis: a rare combination of colonic adenocarcinoma and undifferentiated small cell carcinoma].

Neuroendocrine or small cell cancer (SCC) is a rare tumor, accounting for less than 1% of all colorectal cancers. There is a high rate of metastasis in SCC. Overlying adenomas are commonly present in colorectal SCC. We present a case of a 67-year-old female patient with liver metastasis of SCC. Initially, the primary tumor was not found and the patient underwent chemotherapy. Ten months later, an adenocarcinoma of the right hemicolon was endoscopically diagnosed due to anal hemorrhage and right hemicolectomy was performed. Microscopic examination revealed that the adenocarcinoma was combined with an undifferentiated carcinomatous component. Immunocytochemistry was positive for synaptophysin and chromogranin. In our case a very rare combination of colonic adenocarcinoma and SCC within an overlying adenoma was found.

Adenocarcinoma↗
PubMed2000

Rounded atelectasis in a patient with history of asbestos exposure. A case report.

We report a case of a 68-year-old patient with a history of chronic asbestos exposure and a lung tumour, highly suspicious for bronchial carcinoma. The patient underwent left lower lobectomy and histology showed the rare diagnosis of rounded atelectasis. Rounded atelectasis is an important differential diagnosis to bronchial carcinoma.

Aged↗
PubMed2000

[Traumatic rupture of the pancreas and duodenum in pre-existing penetrating duodenal ulcer].

Pancreatic injuries are rare complications after blunt abdominal trauma and usually the result of a direct force separating the pancreatic body in front of the vertebral column. This case report describes the uncommon event of a severe pancreatic and duodenal injury (stage IV b of Lukas) in which the combination of a direct force and the setting of a preexisting penetrating ulcer of the duodenum caused the extent of the pancreatic and duodenal injury [9]. Because of the preexisting lesion a Whipple procedure had to be performed. This case report demonstrates the influence of chronic abdominal diseases on the outcome of blunt abdominal trauma.

Abdominal Injuries↗
PubMed1997

[Extramedullary plasmocytoma of the bronchial system].

We present a case of primary plasmocytoma of the left upper bronchus. Occlusion led to atelectasis of the left upper lobe and subsequent poststenotic pneumonia. Therapy consisted of local excision of the bronchus and postoperative radio-therapy. This type of lung-conserving therapy in a case of primary plasmocytoma has not been described before.

Bronchi↗
PubMed1996

Value of bronchoscopic pneumonia diagnosis: prospective study.

In a prospective clinical study we examined whether bronchoscopically controlled suctioning is preferable to the blind suctioning of mucus aspirates for bacterial identification of intensive care unit patients with pneumonia. Forty patients with clinical and radiologic signs of pneumonia underwent both bronchoscopically controlled and blind endotracheal lavage. Bronchoscopically controlled suctioning did not demonstrate greater sensitivity for identifying organisms than the results obtained from blind suctioning (58 organism were bronchoscopically identified, compared to 57 organisms identified by blind suctioning; p = 0.32, NS). Arterial and mixed venous partial oxygen pressure and shunt also showed no significant differences 15 minutes before and after examination, nor did the blood pressure or pulse. The use of four of the bronchoscopes resulted in preinterventional contamination with Pseudomonas. Bronchoscopically controlled lavage shows no advantages over blind endotracheal lavage for diagnosing pneumonia. Blind suctioning with single-use sterile catheters can be done more quickly and inexpensively with fewer personnel and a lower complication rate.

Adult↗
PubMed1996

[Multiparity in Nicaragua].

The relation between birthweight and parity of the mother was examined in Nicaraguan patients from the capital Managua. 7431 births were taken into consideration from 1989-1991. 564 (= 7.6%) of these newborns were born to mothers with more than 5 deliveries. A positive correlation between the increasing number of the parity and the birthweight can be demonstrated in our patients until parity 10, however there are decreases in the birthweight of female newborns between parity 3 to 4 and 5 to 6 and in males between parity 6 to 7 and parity 8 to 9. The average age of a Nicaraguan primipara is 20.7 years and increases by 1.9-2.4 years until parity 5. From parity 6 to parity 15 it increases only by 0.7-1.2 years.

Adult↗
PubMed1996

[Clinical results of extremity perfusion in malignant melanoma].

Side effects and results of isolated hyperthermic extremity perfusion in malignant melanoma at the University of Cologne were reviewed: Severe local and systemic side effects (WHO grade III, IV) occurred in 3%, 5-year survival rates were 100% in TNM stage I patients (n = 27), 88.7% in TNM stage II patients (n = 123), 46.4% in TNM stage III patients (n = 169) and 36.3% in TNM stage IV patients (n = 22). 5-year recurrence free survival rates were 100% in TNM stage I, 73.4% in TNM stage II, 20.8% in TNM stage III and in TNM stage IV 9.1%. Indication for extremity perfusion remains locoregional recurrent disease.

Adolescent↗
PubMed1996

[Value of regional lymph node excision for prognosis of advanced malignant melanoma treated by perfusion of the extremity].

Staging by means of preoperative clinical screening will always stage melanoma study patients too favourably. Only a postoperative histopathological staging by means of lymphadenectomy will allow a correct stage-correlated patient prognosis. Lymphadenectomy does not prolong overall survival (95% confident intervals +/-6.6% to +/-25%) however prolongs recurrence free survival.

Antineoplastic Agents↗
PubMed1995

Isolated hyperthermic perfusion with mitoxantrone of melphalan in malignant melanoma of the limb.

BACKGROUND: Melphalan administered by isolated hyperthermic perfusion of the affected limb is an accepted treatment for malignant melanoma of the extremities. In contrast, pharmacologic and phase I studies suggest that, because of its high uptake, mitoxantrone may give even better local control, but data on survival, onset of metastases, and local and systemic toxicities have not yet been reported. METHODS: A matched-pairs comparison was performed to examine differences in the tolerability and effectiveness of isolated hyperthermic extremity perfusion with mitoxantrone (n = 44) and melphalan (n = 44) in high risk and locoregionally (P < 0.41) metastatic malignant melanoma. Criteria evaluated were local and systemic complications, and recurrence-free and overall survival. RESULTS: Local complications, such as delayed wound healing, were more frequent in the mitoxantrone (27.9%) than in the melphalan group (9.8%) (P < 0.05). Systemic toxicity, in particular bone marrow toxicity, was also more severe with mitoxantrone (78.6% versus 15.4%, P < 0.001). Hepatotoxic effects were more frequent among patients in the melphalan group who were older and has lower tissue perfusion temperatures (P < 0.05). There was no difference between the two groups in overall or recurrence-free survival (P < 0.41). CONCLUSIONS: Local and systemic toxicity seem to be higher with mitoxantrone. Survival rates were similar with both drugs. The data obtained suggest a randomized phase II study with an appropriate number of patients.

Adult↗
PubMed1994

Mechanisms in nickel genotoxicity: the significance of interactions with DNA repair.

Even though nickel compounds are strong carcinogens, the underlying mechanism is still unclear. In contrast to their weak mutagenic potential, they enhance the cytotoxicity and genotoxicity of UV light, X-rays and cytostatic agents like cis-platinum, trans-platinum and mitomycin C. Studies in combination with UV light indicate an inhibition of DNA repair, presumably at the incision step of nucleotide excision repair. Possible reasons for repair inhibition are structural changes of the DNA or direct interactions with repair enzymes or proteins, possibly by competition with essential metal ions.

Animals↗
PubMed1991

Clinical pharmacokinetics of mitoxantrone in hyperthermic, isolated perfusion of the leg.

The clinical pharmacokinetics of mitoxantrone in hyperthermic, isolated perfusion of the leg were studied in five patients exhibiting solitary, localized malignant melanoma. Mitoxantrone was given as four 1-min infusions at 15-min intervals into the arterial line of the perfusion system at a total dose of up to 14 mg/m2. The mean half-lives for mitoxantrone in the blood circulation of the leg were: t1/2 alpha (distribution phase), 25.5 s, and t1/2 beta (elimination phase), 14.9 min. The mean volume of distribution at steady state in the leg was 25.6 1. In the arterial part of the perfusion, the mean AUC was 155.9 mg min l-1, and that in the corresponding venous part was 91.6 mg min l-1. Leakage of the drug from the leg into the systemic circulation amounted to 1.2% of the total delivered dose; 91% of the delivered dose remained in the leg after the perfusion had been completed. The mean elimination half-life of mitoxantrone in the systemic circulation was 123 min and the corresponding AUC for systemic concentrations was 8.59 mg min l-1. The present data revealed a high uptake of mitoxantrone into the leg and low systemic drug concentrations due to minor leakage, suggesting that mitoxantrone might be a good candidate for use in isolated, hyperthermic limb perfusion.

Adult↗
PubMed1990

The value of current staging systems for melanoma of the extremities.

The validity of current staging systems for malignant melanoma was analyzed in a prospective study on 220 patients with extremity melanoma. Patients were followed 2 to 9 years after a wide excision of the primary, regional cytostatic perfusion and dissection of regional lymph nodes. The "original three-stage" system yielded statistically significant differentiation, but with a distinct preference for Stage I. The classification into IA/B, and IIIA/B/C according to the M.D. Anderson system does not distribute the patients into significantly different tumor stages. Using the American Joint Committee of Cancer Staging and End Results Reposting (AJCC) system, 40 patients were classified as Stage I, 95 as Stage II, 53 as Stage III, and 32 patients as Stage IV. The 5-year survival rate was 96% in Stage I, 90% in Stage II, 68% in Stage III, and 30% in Stage IV. According to the UICC staging system there was a numerical preference of Stage II and III. The differentiation of Stage I and II was not significant. It is the authors' opinion that the AJCC staging system allows the best differentiation of melanoma patients into tumor stages that are evenly distributed and significant for prognoses.

Adult↗
PubMed1990

Symptoms, diagnosis, and therapy of primary sarcomas of the pulmonary artery.

Primary sarcoma of the pulmonary artery is a rare tumor which must be considered in differential diagnosis of pulmonary embolism. The data of the 93 cases published up to now is evaluated synoptically after a report on a primary sarcoma of the pulmonary artery. Modern diagnostic imaging methods (pulmonary DSA, perfusion scintigraphy, echocardiography, computer tomography, nuclear magnetic resonance tomography) may corroborate the suspicion of a sarcoma of the pulmonary artery. With a median survival time of 1.5 months, the prognosis of patients with primary sarcomas of the pulmonary artery must be regarded extremely poor. After tumor excision, the median survival time of the patients could be prolonged (statistically significant; p less than 0.01) to ten months. The significance of adjuvant chemotherapy and/or radiotherapy cannot be appraised at present.

Diagnosis, Differential↗
PubMed1990

[Multi-parity in Saudi Arabia].

The relation between birthweight and parity of the mother was examined in Saudi patients from Tabuk and Najran. 4,664 newborns were taken into consideration from 1985-1988. 30.7% (1,430) of these newborns were born to mothers with more than 5 deliveries. A positive correlation between the increasing number of the parity and the birthweight can be demonstrated in our patients from parity 9. From parity 9 to parity 11 there is an increasing birth-weight of the male newborns, whereas the weight of the female newborns shows different tendencies. The average age of a Saudi primipara is 20.5 years and increases by 1.05-1.99 years until parity 11. From parity 11 to parity 13 it increases by 0.7 years.

Adult↗
PubMed1989

[The prognosis of patients with level V melanomas of the extremities].

Patients with level V melanoma have a very bad prognosis on account of their high rate of lymph node and distant metastases. From Jan. 1979 to Dec. 1987, a total of 251 patients suffering from malignant melanoma of the extremities (including 28 patients with level V melanoma = 11.2%) underwent excision of the primary tumor, lymph node dissection, as well as regional hyperthermic perfusion with cytostatics. The prognosis of our patients with level V melanoma could be improved considerably by therapy.

Adult↗